Various types of wheel bearing devices are developed, including a first generation type in which double-row rolling bearings are used in combination, a second generation type in which a body mounting flange is provided integrally with an outer member, a third generation type in which one of the two inner raceway surfaces of a double-row rolling bearing is formed on the outer periphery of a hub, and a fourth generation type in which one of the two inner raceway surfaces of a double row rolling bearing is formed on the outer periphery of a hub and, at the same time, the other inner raceway surface is formed on the outer periphery of an outer joint member of a constant velocity universal joint.
For example, Patent Document 1 discloses the third generation type of a wheel bearing device. As illustrated in FIG. 40, the third generation type of the bearing device for a wheel is provided with a hub 152 having an outwardly extending flange 151, a constant velocity universal joint 154 having an outer joint member 153 to be fixed to the hub 152, and an outer member 155 arranged on the outer side of the hub 152.
The constant velocity universal joint 154 is provided with the outer joint member 153, an inner joint member 158 arranged within a mouth portion 157 of the outer joint member 153, a ball 159 arranged between the inner joint member 158 and the outer joint member 153, and a retainer 160 retaining the ball 159. Further, a female spline 161 is formed on the inner diameter surface of the center hole of the inner joint member 158, and a male spline formed at an end of a shaft (not shown) is inserted into this center hole. Through fit-engagement of the female spline 161 on the inner joint member 158 side and the male spline on the shaft side, the inner joint member 158 and the shaft are connected together so as to allow torque transmission.
Further, the hub 152 has a cylindrical portion 163 and the flange 151. A short-cylinder-like pilot portion 165 for attaching a wheel and a brake rotor (not shown) protrudes from an outer end surface 164 (out-board side end surface) of the flange 151. The pilot portion 165 includes a large diameter portion 165a and a small diameter portion 165b, and the wheel is fitted onto the large diameter portion 165a, and the brake rotor is fitted onto the small diameter portion 165b. 
A fit-engagement portion 166 is provided on the outer peripheral surface of the in-board side end portion of the cylindrical portion 163, and an inner ring 167 is fit-engaged with the fit-engagement portion 166. A first inner raceway surface 168 is provided on the portion of the outer peripheral surface of the cylindrical portion 163 in the vicinity of the flange 151, and a second inner raceway surface 169 is provided on the outer peripheral surface of the inner ring 167. A bolt attachment hole 162 is provided in the flange 151 of the hub 152, and a hub bolt for fixing the wheel and the brake rotor to the flange 151 is attached to the bolt attachment hole 162.
The outer member 155 of the rolling bearing has in its inner periphery two outer raceway surfaces 170 and 171, and, in its outer periphery, a flange (vehicle body mounting flange) 182. The first outer raceway surface 170 of the outer member 155 and the first inner raceway surface 168 of the hub 152 are opposed to each other, and the second outer raceway surface 171 of the outer member 155 and the raceway surface 169 of the inner ring 167 are opposed to each other, with rolling elements 172 provided between the opposing surfaces.
A shaft portion 173 of the outer joint member 153 is inserted into the cylindrical portion 163 of the hub 152. A screw portion 174 is formed at a shaft end portion of the shaft portion 173, and a male spline 175 is formed on the outer peripheral portion on the in-board side of the screw portion 174. A female spline 176 is formed on the inner diameter surface of the cylindrical portion 163 of the hub 152. By forcing the shaft portion 173 into the cylindrical portion 163 of the hub 152, the male spline 175 on the shaft portion 173 side and the female spline 176 on the hub 152 side are fit-engaged with each other.
Further, a nut member 177 is screwed on the screw portion 174 of the shaft portion 173, and the hub 152 and the outer joint member 153 are fixed to each other. In this process, a bearing surface 178 of the nut member 177 and an outer end surface 179 of the cylindrical portion 163 abut each other, and an out-board side end surface 180 of the mouth portion 157 and an end surface 181 of the inner ring 167 abut each other. As a result, the hub 152 is held between the nut member 177 and the mouth portion 157 through the intermediation of the inner ring 167.    [Patent Document 1] JP 2004-340311 A